Ski



FIG. 1 is a side view of the design from the left;

FIG. 2 is a top view;

FIG. 3 is a side view from the right;

FIG. 4 is a bottom view;

FIG. 5 is a front view;

FIG. 6 is a back view; and,

FIG. 7 is a perspective view of the design. 

The ornamental design for a ski, as shown. 